Atlantic Fleet is turn based where one gives movement and then fire orders. There are 19 historical Atlantic scenarios such as Graf Spee, Bismarck, HMS Glorious. There is a campaign that has your navy patrol and then get into battle what they find. I found it unrealistic, but interesting. However note that all WWII naval sims are arcade to me.

Cold Waters is a modern sub sim that is real time and better. Ive only gone thru half the training so far, and I do like it so far. It would be top notch if it was multiplayer, but then that would mean sim of surface ships as well.